


Star Spangled Rover

by sdwbf



Category: Marvel Avengers Movies Universe, The Avengers (2012)
Genre: Animal Transformation, Bestiality, M/M, Sex with Sentient Animals
Language: English
Status: Completed
Published: 2012-09-02
Updated: 2012-09-02
Packaged: 2017-11-13 10:20:28
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,233
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/502471
Author URL: https://archiveofourown.org/users/sdwbf/pseuds/sdwbf
Summary: <blockquote class="userstuff">
              <p>Loki transforms Steve into a dog for six months. And the funny part? It's all because Loki is doing Tony a favor. Written for <a href="http://avengerkink.livejournal.com/6148.html?thread=10334212#t10334212">this prompt</a> on the Avengerkink meme.</p>
            </blockquote>





	Star Spangled Rover

**Author's Note:**

> This is my first attempt at avoiding an avalanche of Tony-angst and cutting pretty much straight to the smut. I'm not sure what to think of it, but I couldn't resist the prompt especially once my mind found a reason for Loki to do this something other than revenge or general mischief.

Tony Stark was the first to admit he led an unorthodox life even before a business trip to Afghanistan had led to an arc reactor in his chest and a part-time gig as a superhero. Of course post-Iron Man things had gone rapidly from unorthodox to downright weird. Case in point? His best friend was a god and had tried to destroy the world, not to mention had come close to killing both Tony and a friend (just don't tell Coulson he'd called him that) of his.

But such was the reality of Tony's 'brave new world' that the whole 'alien invasion/attempted murders/etc.' thing came under the heading of 'nevermind' because it had turned out Loki had been under the same sort of mind control whammy he'd hit Dr. Selvig and Clint Barton with. No one had even considered the idea since Loki's eyes hadn't had that tell-tail cosmic-blue swirly glow to them, but when Thor had taken his errant brother home Odin had spotted the problem in an instant. Apparently Asgardians didn't get the same helpful special effects clue as Midgardians. Go figure. In any case, since Clint and Selvig had gotten an 'all is forgiven' pass on their part in the brief war, Loki had, too.

But because he'd been a bad, bad boy prior to the whole getting captured and brainwashed thing, Loki had also been sentenced to 'community service' on Midgard and had Tony mentioned that's what Thor and crew called Earth? There had been a lot of bellowing of the 'hell no!' variety, but, in the end Loki had become the newest, if part-time, resident of Stark Tower. He wasn't an Avenger, although he helped out from time to time. Mostly he wandered the world doing a variation on what the Norse had worshipped him for – showing others the error of their ways via tricks and schemes. In between those tricks, he popped into the Tower to recharge.

Since Tony kept weird hours even in comparison to the other Avengers – which was saying a lot – Loki had started out pestering him when he wanted company. Somehow pestering had turned into friendship and Loki had joined the official ranks of Tony Stark's Best Friends. Yes, he knew 'best' implied one, but Tony refused to choose an overall favorite among those dumb enough to actually _like_ spending time with him.

Other things happened during that post-invasion year besides the development of an improbable friendship and the rebuilding of New York City required by that aforementioned invasion. Within a week of it, his attempt at a romantic relationship with Pepper Potts had crashed and burned into a friendship free of sexual attraction and full of affection. He'd had no regrets on that point and had even given the bride away when Pepper had married Phil Coulson last month.

Of course, something else had happened during the year to make that happy moment a lot easier on Tony. Something that ranked right up there in the life-changing power of the arc reactor in his chest – Tony and Steve Rogers had fallen in love. Given their rocky first-impressions of one another – a politer way of saying they'd hated each other – it was a shock for both of them, but they'd gone from begrudging teammates to friends to dating to crazy about each other.

So Tony had suddenly found himself a part of a team, surrounded by friends and deeply in love. Life had been scary good right up until his birthday. Well, to be accurate, the day itself had been great due to all those friends. The celebration had been fun, the food incredible and the running commentary of witty comments from Rhodey, Clint and Loki had made him laugh so hard his ribs had ached. It wasn't until he'd woken up in the wee hours of the next morning to the sound of Steve crying that it had all come to an abrupt halt.

It had taken until dawn to coax what was wrong out of his devastated lover, but it turned out one person at the party hadn't found all those 'old man' jokes funny. Tony had cursed himself a fool and had wanted to kick several asses including his own for not thinking about how Tony growing old would affect a man who was 1) younger physically by 10 years, 2) had already lost everyone he'd loved from one life time and 3) was aging slowly enough he'd have to do go through a similar loss at least two more times.

Tony had not tried to console Steve by pointing out the life expectancy of superheroes and the unlikelihood of any of them living into true old age. Instead he'd held Steve until his lover had calmed enough to fall into an exhausted sleep. While Steve had apologized for worrying Tony and had insisted he was all right that it had all been the result of a bad dream, the man had been subdued for days.

It had led to Tony commiserating with Loki during his next visit. He'd even made Loki swear he would look after Steve when Tony and the rest of the Avengers had gone. Loki had gotten a look like he'd smelled rotten meat – their friendship had not translated into warm feelings between Loki and the others – but had agreed. Tony had thought that was the end of it. Then had come the apple juice incident.

Tony, Clint and Bruce had all stumbled into the kitchen for their morning coffee and had ended up with a mouthful of apple juice instead of caffeinated goodness. Their respective spit takes had all been followed by a loss of years. Physically, not mentally, they'd all reverted to 30. Or more like their bodies had renewed themselves because while all post-30 scars had vanished – including one he remembered getting on his 31st birthday, hence the ease at pinpointing their ages – the arc reactor had remained buried in his chest while Bruce could still sense the Hulk lurking inside. A genius who had apparently confided in the wrong god, Tony had quickly put together the lack of anything but real coffee in Natasha's mug – she was 28 and needed no backward help to 30 – and their respective ages now matching Steve's and had retreated to his workshop to call Loki and yell.

Turned out he'd put a hint of the essence of the apples used to grant the denizens of Asgard near-mortality into their cups then added a magic twist and had taken the necessary years off the top. And sorry, no refunds, since the apples couldn't do the fast forward thing, although nothing Loki had done would stop them from aging forward from their new set points.

Tony had forced himself to calm down by concentrating on the fact that Loki had meant well – although he'd already figured out it was more to avoid having to keep his promise than to help out and Tony could have seriously done without the inevitable media frenzy over his 'face lift.' Then he'd patiently explained it wouldn't work. Steve would still out live them all by at least one more full lifetime and no take-backs on his promise.

In retrospect, Tony guessed he had no one to blame but himself for breaking down and confiding in Loki instead of waiting until Thor had come back from a tryst with Jane, but hindsight was a bitch. Especially when it explained why he'd woken up with a large dog in his bed instead of a handsome super-soldier.

God, Tony hated his life at times. Especially when he could look at what was superficially an overly-huge Golden Retriever with long legs and blue eyes and _know_ he was looking at … Sigh. "Steve."

The dog whined.

Fuck. "Bark twice if you're you in there."

Two barks answered, so Steve was still Steve between the ears and was that the good or bad news? He snatched his phone off the end table and hit Loki's name with enough force it made hisfinger ache. Damned thing went straight to voice mail, and he was going to have to program an override for that sort of maneuver. "Get your ass here, now!" he snapped.

He spent the next hour doing a question and answer thing – two barks for yes; three for no – to test how much of Steve still remained. And was it strange that he was more thankful for his soundproof walls hiding the barking versus his rather vocal enthusiasm when Steve fucked him from the others?

"I promise you he's mentally unchanged," Loki said during a pause while Tony tried to think of another question.

Steve growled, putting his furry body between Tony and Loki's sudden arrival, but before he could decide to go for the god's throat – something Tony didn't think would work out well for any of them – Tony wrapped his arms around him and held on. "What. The. Hell?"

"It is the answer to your dear Captain's dilemma," Loki answered, then smirked. "Although I suppose it is a tad unconventional."

"Explain before I get the suit." The 'so I can blast you with my repulsors' was a given.

"I can not fix the aging problem without totally removing the super-serum from his blood stream," he answered. "And that would cause him to revert to his old form. At the age of 100, something he could not survive."

Tony hugged Steve tighter at even the thought of his lover gone. It made Steve give him a reassuring nudge with his snout. And, God, Steve had lived with this fear since he'd defroasted.

"By transforming him, he becomes more a creation of mine than science and I can manipulate the acceleration of a dog's shorter lifespan to burn off the extra human lifetimes without altering anything else. When I have finished I will restore him, but he will age normally." He looked at Steve. "I cannot make promises for humans are fragile and life spans vary too widely among them, but you will be no more likely to outlive Tony than him you."

That sounded like a terrible plan to Tony, who had liked knowing that – all supervillain crap aside – he would not have to endure living without Steve. Which probably made him a hypocrite since Steve's tail began to wag with enthusiasm. Fuck. "How long?"

"Six months," he answered, then vanished.

*

Ask just about anyone about Tony and the first thing they'd mention would be his sexual escapades. As far too many YouTube vids could attest, he'd seldom gone without when he had other options and since he'd gotten horizontal with Steve, he'd been bent over something or other at least twice a day. Given all that, it was a lot to ask him to go through a six-month dry spell without complaint. Even if he was the sort of person who bothered not to complain. Never had seen the merit of that whole suffer in silence bit.

"Steve," he whined doing his best to give a damned dog puppy eyes. "It's been a month!"

The golden head shook and Steve shifted to settle on the far end of their bed.

Tony gave up on using his big eyes for pleading and went back to his natural state of glaring. It wasn't fair. Steve had gone four-legged but he still managed to nag Tony about such piddly matters as sleeping and eating; he hadn't lost his strength or his speed so he could still go on missions and had even got good about making the others understand fairly intricate plans between diagrams scratched on the ground and more dog-like forms of communication. So same old, same old, except Tony hadn't gotten fucked since the night before all of this had happened and he wanted Steve's cock in his ass. Now!

"Look, it's not like you're a real dog."

Steve arched an eye at him sort of making Tony's point since he didn't think dogs could do eye-sarcasm.

"You don't even do real dog things." Hell, Steve used the toilet not the shrubbery, he insisted Tony brush his doggy-teeth twice a day, and he ate people food from a plate sitting at his usual spot at the table. "Well, not unless you count the Frisbee thing." Steve loved playing catch with that thing.

Steve huffed looking unimpressed. And damn Tony's tendency to ramble because he was swiftly losing ground here.

"Damnit, what's the big deal? You're my lover so make love to me!"

Steve shifted to put his back to Tony and why, oh, why had he fallen for a man with a decent moral code? Anyone else would have had a hot, rich, young thing like Tony's ass in the air before he could even finish undressing, but he was an hour into night three of his crusade to get his lover to take that title more literally.

"Fine," he conceded defeat for the third time and he _hated_ losing. Worse, he felt like he was going to come right out of his skin if he didn't get some relief. He supposed that was his answer. 'Some' might not be preferable to Steve, but it was better than nothing. He kicked the sheet off his naked body. "But I'm done going without."

Steve spun around his eyes huge and he whined loudly before Tony could move. It was a heart-broken sound.

"What? What's wrong?" Tony demanded alarmed, quickly taking Steve into his arms. More whines and a possessive paw around his waist somehow told him … Oh, Steve thought … "Idiot, if you're like this for 60 more years I'm still never letting anyone else touch me. But I have this." He waved his right hand. "And I intend to use it."

Steve nuzzled him, licked his face. His 'puppy kisses' were always restrained, more the gentle licks of a person than the wild frenzy of tongue and spit favored by the canine set. Tony smiled. "Love you, too." And thank any god but Loki he had manned up and told Steve that before the paws because he would have hated for the first time he'd said the words to have been post-fur, but pooch-Steve needed to hear them. A lot. Was almost as needy and mopy about it as Tony had been pre-fur. Damn, they were a pair.

He tried to settle down and simply snuggle until they fell asleep, but his body refused to cooperate. Never sleep if he didn't give in and Steve fussed when he didn't sleep. He sighed. "I'm sorry, babe, but I've got to do this." He glanced toward the bathroom. Been a long time since he'd had to retreat to the men's room to jerk off, but, "Do you want me to … take a shower?" Stupid way to put it since he'd taken one before dinner to wash off the workshop grease.

Steve shook his head so Tony shifted upward on the bed, giving them some space before he wrapped his hand around his cock. He settled into the stroke, pull pattern he favored but knew it wouldn't be enough. It seldom was. He lifted his left hand to his mouth and slicked a finger with saliva, then pushed it into his ass while he continued to work his cock with his right.

Better but still inadequate. Always had been a size queen and Steve was well-endowed. Had made his hole greedy as fuck, but it would have to take what it could get. He made a sound – a mixture of pleasure and frustration – and the mattress shifted.

He assumed Steve was jumping off the bed, but instead he walked up the length of it. Curious Tony opened eyes he didn't remember closing and watched Steve pull open the drawer where they kept the toys. A second later he had the dildo he liked pushing into Tony while Tony gave him a blow job clutched in his jaws. He dropped it next to Tony's hip, then dove back into the drawer this time emerging with the bottle of lube. "Thanks, babe," Tony whispered, picking both up. Only took a moment to slick the silicone, then ease it inside himself. "Always take such good care of me."

Steve gave his lips a single lick, then curled up around Tony's head, watching as he fucked himself into orgasm. Did the same thing the next two weeks. For the week after that he got out the supplies as Tony undressed for bed in a clear demand for him to put out. Tony had smirked and obeyed, moaning his lover's name even as he thrust the toy roughly in and out of his hole.

Tony could always see the angry red of Steve's cock hanging free from its sheath and oozing come when he finished shuddering through his own climax. Finally as they entered their fourth week of alternative-sex, he decided lust might have had enough time to weaken Steve's resolved, and he moved the hand he'd spilled on slowly up the bed, letting Steve take in the approach and decide what he wanted.

Steve whined. A weak protest, but it made Tony stop his advance and wait, until Steve whined again and licked his forehead. He smiled and took hold of the cock. Took a few minutes to get just the right motion and grip, but he soon had Steve spilling into his hand. And spilling and spilling – for a full 26 minutes.

Tony wiped their combined spunk onto the butt plug he always wore under his tux – made boring events so much more fun especially when Steve knew it was there – then pushed it inside his still wet hole. Steve licked his lips again and did so again when Tony's lips parted. They Frenched for the better part of an hour – Tony had missed the kissing almost as much, if not more, than the fucking so he loved every moment. Finally, he fell asleep wrapped in Steve's four legs. The next few nights were a rinse, repeat sort of thing.

Then one morning he woke up to Steve's tongue probing his ass. Either the plug had come out in the night or, more likely, Steve had pulled it out with his teeth then he'd started lapping. Fortunately Steve loved playing with Tony's ass as much as Tony loved having it played with and the canine-version of his tongue was particularly talented at rimming him. Had Tony writhing in moments and he came without touching his cock. While he lie there panting through the aftershocks, Steve managed to ease the plug back into his ass, and Tony wiggled happily at the sensation. Morning rimming meant a blow job reward and he shifted over onto his back, mouth already watering, even as he wondered if Steve would allow it.

His lover stared at him for several minutes, obviously trying to make a decision about lines crossed and lines yet remaining. Fortunately, things went Tony's way – he'd been told post-orgasm was a very good look for him. Steve shifted up onto all fours and straddled Tony's face, his unsheathed cock hanging down in a dark red demand for attention. Tony didn't hesitate to take it into his mouth and hummed happily to find that while there was a different nuance to it, both flesh and seed still tasted like Steve. And oh, hey, the knot. Took a little effort to get his lips around the tantalizing bulb but he managed to take it, sucking away while Steve fucked his mouth with enthusiasm. When he finished, Steve pulled out, then nudged Tony toward the bathroom.

He laughed, a little hoarse from being so well used. "Right, time for a different meal," because fucking burned almost as many calories as super-soldiering. Tony hurried through his usual shower routine, dressed then headed to the kitchen to whip up pancakes and lots of bacon.

They enjoyed a long, leisurely breakfast with the team, then everyone headed off. Except when Tony tried to go down to his workshop, Steve's teeth hooked onto the back of his jeans and pulled in the opposite direction. "What?" he asked. "Is Timmy in the well?"

Steve gave him a 'that stopped being funny the third time you used the line' look, then nudged Tony toward their bedroom. "Oh, barefoot and pregnant day for me, is it?"

That earned him a firm nod and another push toward the bedroom. "Yes, dear," he chuckled and obeyed. He began shedding his clothes the moment he crossed the threshold. Steve barked his approval when he was naked and fetched the bottle of lube, but not the dildo.

"Finally decided to knot your bitch?" he asked, taking the bottle. Another enthusiastic bark made his hands tremble in anticipation, but it had been too long since he'd had Steve's bulk inside him, so he took the time to get himself wet and loose before he dropped to his hands and knees.

Steve mounted him the moment he settled into position. His cock finding Tony's hole on the first eager practice, but then Cap had always had good aim. He groaned, welcoming the hot length pushing into him. Steve's paws clutched him, holding him in position as he went to town on Tony's ass. Thrusting harder and faster than his human form ever had, he banged away on Tony's prostate making him squeal and writhe as much as he could while held so firmly. God, he loved this. Had always loved it when Steve wanted him so much he forgot himself and used him.

He felt the press of the knot against his hole and Tony braced himself against the rabbit thrusts that worked the huge thing into him. He couldn't stop the scream. Some of it was pain, but most of it was from a pleasure so great he was almost afraid it would short out his reactor. Breeding him. Steve was breeding him. Had tied them together with his monster cock and knot, trapping his bitch as he pumped his seed into Tony's belly, trying to fill it with his puppies. Stupid thought, but it made Tony come, his ass eagerly milking the knot for every drop of seed it could get.

Steve's knot apparently liked Tony's snug little ass more than his mouth and they stayed knotted for a good thirty minutes before Steve pulled out. He licked first Tony, then himself clean, an act that made his canine cock all hot and ready for round two. Apparently Tony had created a monster. Not that he had any complaints.

He remained complaint-free days later when he was still spending the majority of his days hanging from Steve's knot. But he'd begun to worry Fury and SI's board of directors might not like another four months of inactivity due to Tony constantly servicing his stud. So he used his knot-free moments to design a fucking bench that would let him work with they were tied. Amazing how productive and creative he got working with Steve's knot throbbing away inside of him. Made up for all the times his mind was so blown he wasn't certain he knew his own name.

They were up to tying for an hour – Tony had to wear a plug most of the time to keep from leaking all over the Tower – and he'd almost finished the final touches on his Mark IX armor when Steve stiffened. A moment later the ass pressed against his got a hell of a lot smoother, and Tony looked over his shoulder to see his human lover for the first time in months. Huh, time had gone a lot faster than he's expected, and how exactly was it they were still tied and ass to ass because as far as he knew the human cock didn't work that way? Steve turned, a reverse of his canine-form's earlier actions and wrapped his arms around Tony. "Hey, beautiful," he murmured into Tony's shoulder.

Tony did his own careful turning -- and yes, there was definitely still a knot plugging his ass -- so he could settle into Steve's embrace. "Missed you," he said when they'd finally gotten their limbs where they wanted them.

Steve smiled his beautiful, blinding smile. "Love you," he whispered before capturing Tony's lips in a deep, long kiss. When Steve's knot deflated enough to withdrawal, he began thrusting again instead, retying them so they had another long lazy hour to exchange kisses and soft words before emerging from the workshop to announce Steve was human again.

Mostly. His cock went back to a more human structure, so no more turning, but he kept the knot meaning Tony still spent at least a couple of hours a day working away while hanging off it. Just had to modify the bench a little to make the new configurations work.

Funny how happy endings worked. Somewhere out there in the multiverse Tony figured Loki had tinkered with Tony's lifespan so he grew old no faster than a Steve with a completely human cock. He supposed that version of them was happy enough, but even with Steve always at his side, Tony couldn't have imagined enjoying watching others he loved age and die while he stayed young. So yeah, he preferred Steve joining him in a human's regularly scheduled expiration date. And, no, he wasn't strong enough to resist the pun – the knot made sure his end was very happy indeed.

end


End file.
